No one can ever know.
However we can have a good guess, that on the balance of probability, and the stars lining up, our bench for a CL semi would have looked a little different to:
Dier
Walker-Peters
Sissoko
Foyth
Gazzaniga
Davies
Skipp
Two full backs, a CB who was played as a fullback, a keeper, Dier, a crocked Sissoko (who was magnificent when he came on) and a teenager that the manager seems to have no confidence in.
As I've said many times, you build a squad that can sustain you through, injuries, suspensions and loss of form.
We're suffering from all three at the moment!
The only squad that could sustain themselves through an injury list like ours is Citeh's. Every other Premier League side would have the same problems as us.